1. Field of the Invention
The present invention relates in general to conductive material, and more particularly to contact pads for the fabrication of semiconductor devices and circuits.
2. Background
During the fabrication process of a semiconductor device, a manufacturer typically performs tests at various stages of the process to ensure that the device is functioning properly. While these tests are being performed, sensors or probes are usually brought into contact with pads on the surface of the semiconductor device. Unfortunately, bringing probes into contact with the pads frequently scratches the pads.
These scratches can contaminate the fabrication environment by introducing particles of the pad material into the environment. Furthermore, the scratches can reduce the reliability of further testing by damaging the contact area between the probes and the pads. If the fabrication environment becomes contaminated or the testing procedures become unreliable, then the fabrication process may yield devices that do not function properly.
To function properly, conventional pads exhibit certain properties, such as low resistivity and good adhesion to the semiconductor substrate. Unfortunately, materials having these properties usually lack sufficient hardness to resist scratching when brought into contact with test probes. Conversely, materials having sufficient hardness to resist scratching generally exhibit high resistivity or poor adhesion to the semiconductor substrate.